Motorists often encounter dangerous situations when they travel at night. Too frequently, a motorist may be distracted or even temporarily blinded by the bright lights or high-beams of either an oncoming motorist and/or a motorist approaching from behind. The resulting reduced visibility endangers drivers on the road (including third-parties), bikers, and pedestrians, as well as property in the surrounding areas. Indeed, a blinded driver might swerve off the road. A blinded driver who slows down risks being “rear-ended,” and a driver who speeds-up risks losing control of the automobile. Furthermore, the chance for an accident is increased because many drivers “retaliate” by turning on their own high beams when they see and are impaired by the high beams of oncoming traffic.
Similar peril exists when other sources of bright light reach the driver's eyes. Other sources might include, for example, spotlights, etc. Like the high-beam example above, a motorist may be blinded by light shining in through the front windshield or through the backlite.
A solution that involves merely tinting the windows may work in daytime situations, but potentially creates even greater hazards in the darkness. Tinting is problematic in that it is continuous and always present. A comprehensive solution must compensate for bright light emanating from a variety of light sources at various times of the day and night.
Thus, it will be appreciated that there exists a need in the art for a method and/or system for reducing visible light transmission of an automobile's front windshield and/or backlite (frequently called the rear window) selectively in response to a variety of situations relating to bright light, at least to help drivers avert accidents.
Therefore, certain example embodiments of this invention seek to reduce the chance of an accident that might ensue when a driver encounters reduced visibility or temporary blindness as a result of light above a certain luminescent threshold. Certain example embodiments of this invention employ a sensor that detects high beams and/or light above a certain threshold, and then reduces the visible light transmission of the front windshield and/or backlite accordingly upon detection of the same. The visible light transmission may be reduced, for example, by using a electrochromic element or by using electrodes to apply a voltage across a gas-filled chamber in the window.
In accordance with certain example embodiments of the present invention, a method is provided for adjusting the visible light transmission of a front windshield and/or backlite. This method may comprise the steps of detecting a light source and determining whether the light source exceeds a threshold luminescence. The visible light transmission of the front windshield and/or backlight is reduced if the light source exceeds the threshold luminescence. Otherwise, if the light source is no longer detected or no longer exceeds the threshold luminescence, the visible light transmission of the front windshield and/or backlight is restored.
In one example embodiment, the visible light transmission of the front windshield and/or backlight is reduced via an electrochromic process. In another example embodiment, the visible light transmission of the front windshield and/or backlight is reduced by using electrodes to apply a voltage across a gas-filled chamber.
In certain example embodiments, the visible light transmission is reduced by at least about 5%, more preferably by at least about 10%, and sometimes by at least about 20% upon detection of high beams and/or light above a predetermined threshold. In certain example embodiments, the visible light transmission of the window is at least 70% when high beams are not detected.
In accordance with another example embodiment of the present invention, a front windshield comprises first and second glass substrates, a low-emissivity (low-E) coating for reflecting radiant energy from the vehicle exterior, a polyvinyl butyral (PVB) layer for reducing the shattering of the first and second glass substrates and laminating the substrates to each other, and an electrochromic layer for adjusting the visible light transmission of the front windshield. Furthermore, a detector for detecting the luminescence of a light source is provided. An electrochromic controller is connected to the electrochromic layer to instruct the electrochromic layer whether and/or to what extent the visible light transmission should be reduced, based on a comparison between the luminescence of the detected light and a threshold value.
In accordance with another example embodiment of the present invention, a front windshield comprises first and second glass substrates, a low-E coating, a PVB layer, and a gas-filled area or gap for adjusting the visible light transmission of the front windshield. The gas-filled area may comprise first and second electrodes with a gap provided therebetween in which gas is housed. Furthermore, a detector for detecting the luminescence of a light source is provided. An electrode controller is connected to the first and second electrodes in the gas-filled area to instruct the first and second electrodes whether and/or to what extent a voltage should be applied across the gas-filled chamber to reduce the visible light transmission, based on a comparison between the luminescence of the detected light and a threshold value.
In accordance with another example embodiment of the present invention, a backlite comprises a glass substrate and an electrochromic layer for adjusting the visible light transmission of the backlite. Furthermore, a detector for detecting the luminescence of a light source is provided. An electrochromic controller is connected to the electrochromic layer to instruct the electrochromic layer whether and/or to what extent the visible light transmission should be reduced, based on a comparison between the luminescence of the detected light and a threshold value.
In accordance with another embodiment of the present invention, a backlite comprises first and second glass substrates with a gas-filled area or gap therebetween for adjusting the visible light transmission of the backlite. The gas-filled area can comprise first and second electrodes. Furthermore, a detector for detecting the luminescence of a light source is provided. An electrode controller is connected to the first and second electrodes in the gas-filled area or gap to instruct the first and second electrodes whether and/or to what extent a voltage should be applied across the gas-filled chamber to reduce the visible light transmission, based on a comparison between the luminescence of the detected light and a threshold value.
In other example embodiments of this invention, method of adjusting the visible light transmission of a vehicle window such as a windshield or backlite upon detection of high beams, the method comprising: detecting a light source; determining whether said light source exceeds a threshold luminescence; when it is determined that the light source exceeds the threshold luminescence, implementing a pulsed filtering system so that filter of light occurs on a pulsating basis to as to periodically filter out at least portions of predetermined wavelengths of light. In certain example instances, the pulsating of the filtering may be in the form of a square wave, a sine wave or the like.
In other example embodiments of this invention, there is provided a method of adjusting the visible light transmission of a vehicle window such as a windshield or backlite upon detection of high beams, the method comprising: detecting a light source; determining whether said light source exceeds a threshold luminescence; and using a filtering system to cause incoming high beam(s) from other vehicle(s) to appear as a low beam(s) light(s) when said light source exceeds said threshold luminescence.